Fix motion handling

Change to determine paging direction with ACTION_DOWN

Author: devgrapher

OCEBook/app/src/main/java/com/devgrapher/ocebook/ReaderActivity.java

@@ -33,6 +33,7 @@
 import java.util.ArrayList;
 import java.util.Locale;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Stream;
 
 
 public class ReaderActivity extends AppCompatActivity
@@ -221,6 +222,7 @@ public void onBrowsePageInProgress(int spineIndex, int totalSpine, int pageCount
         int percent = (int) ((spineIndex + 1) / (float) totalSpine * 100);
         mPageInfoTextView.setText("" + percent + "%");
 
+
         // reset
         if (spineIndex == 0) {
             mPageCounts = new PageCounts(totalSpine);
@@ -229,7 +231,7 @@ public void onBrowsePageInProgress(int spineIndex, int totalSpine, int pageCount
         // Store page counts for each spine.
         mPageCounts.updatePage(spineIndex, pageCount);
 
-        // done
+        // if done
         if (percent == 100) {
             mPageCounts.updateComplete();
             onPageChanged(mCurrentSpinePage, mCurrentSpine);

OCEBook/app/src/main/java/com/devgrapher/ocebook/WebViewFragment.java

@@ -23,6 +23,7 @@
 import com.devgrapher.ocebook.model.Page;
 import com.devgrapher.ocebook.model.PaginationInfo;
 import com.devgrapher.ocebook.model.ViewerSettings;
+import com.devgrapher.ocebook.util.MotionHandler;
 
 import org.readium.sdk.android.Container;
 import org.readium.sdk.android.Package;
@@ -113,20 +114,17 @@ private void initWebView() {
         mWebView.getSettings().setAllowUniversalAccessFromFileURLs(true);
         mWebView.setWebViewClient(new ReadiumWebViewClient());
         mWebView.setWebChromeClient(new WebChromeClient());
+        mWebView.setOnTouchListener(new MotionHandler(new MotionHandler.OnMotionListener() {
+            @Override
+            public void onMoveNextPage() {
+                mReadiumCtx.getApi().openPageRight();
+            }
 
-        mWebView.setOnTouchListener((View v, MotionEvent event) -> {
-                switch (event.getAction()) {
-                    case MotionEvent.ACTION_UP:
-                        if (event.getX() < v.getWidth() / 2) {
-                            Log.d(TAG, "Touch left");
-                            mReadiumCtx.getApi().openPageLeft();
-                        } else {
-                            Log.d(TAG, "Touch right");
-                            mReadiumCtx.getApi().openPageRight();
-                        }
-                }
-                return false;
-        });
+            @Override
+            public void onMovePreviousPage() {
+                mReadiumCtx.getApi().openPageLeft();
+            }
+        }));
     }
 
     private void initReadium() {

OCEBook/app/src/main/java/com/devgrapher/ocebook/readium/TocHelper.java

@@ -7,8 +7,6 @@
 import java.util.stream.Stream;
 
 /**
- * Created by Brent on 2/17/17.
- *
  * Help to navigate through the Table of Contents.
  * This flattens children tree and caches it.
  */

OCEBook/app/src/main/java/com/devgrapher/ocebook/util/MotionHandler.java

@@ -0,0 +1,53 @@
+package com.devgrapher.ocebook.util;
+
+import android.support.v4.util.Pair;
+import android.util.Log;
+import android.view.MotionEvent;
+import android.view.View;
+
+/**
+ * Hide implementations of motion handling.
+ * This only provides motions that we desired through OnMotionListener.
+ */
+
+public class MotionHandler implements View.OnTouchListener {
+
+    private static final String TAG = MotionHandler.class.toString();
+    private final OnMotionListener mMotionListener;
+
+    private Pair<Float, Float> mStartPos;
+
+    public interface OnMotionListener {
+        void onMoveNextPage();
+        void onMovePreviousPage();
+    }
+
+    public MotionHandler(OnMotionListener listener) {
+        mMotionListener = listener;
+    }
+
+    @Override
+    public boolean onTouch(View v, MotionEvent event) {
+        switch (event.getAction()) {
+            case MotionEvent.ACTION_UP:
+                if (mStartPos != null) {
+                    if (mStartPos.first < v.getWidth() / 2) {
+                        Log.d(TAG, "Touch left");
+                        mMotionListener.onMovePreviousPage();
+                    } else {
+                        Log.d(TAG, "Touch right");
+                        mMotionListener.onMoveNextPage();
+                    }
+                    mStartPos = null;
+                }
+                break;
+            case MotionEvent.ACTION_DOWN:
+                mStartPos = Pair.create(event.getX(), event.getY());
+                break;
+            case MotionEvent.ACTION_CANCEL:
+                mStartPos = null;
+                break;
+        }
+        return false;
+    }
+}